Nonwoven fabrics

ABSTRACT

Oriented film is fibrillated between two belts of elastic material by distending the belts in a direction transverse to the direction of orientation of the film by passing pressure means across and in contact with at least one elastic belt so that the component of the velocity of the pressure means that is parallel to the direction of movement of the film is substantially equal to the velocity of movement of the film.

United States Patent Leroy E. Robinson;

Dan E. Perry, Bartlesville, Okla. 749,506

Aug. 1, 1968 Di\ ion of Ser. No. 442,588, Mar. 25, 1965, Patent No.3.424.358.

Jan. 12, 1971 Phillips Petroleum Company a corporation of Delawareinventors App]. No. Filed Patented Assignee NONWOVEN FABRICS 8 Claims, 5Drawing Figs.

U.S. Cl 225/93, 28/ l B26f 3/02 Int. Cl Field of Search 98: 28/1 F:264/(fibrillating digest); 83/326 [56] References Cited UNITED STATESPATENTS 3,111,052 11/1963 Engel 83/326X 3,154,986 11/1964 Reid 83/326X3,235,644 2/1966 Rasmussen.. 225/3UX 3,350,491 10/1967 Rasmussen 225/3UXPrimary Examiner.lames M. Meister Attorney-Young and Quigg ABSTRACT:Oriented film is fibrillated between two belts of elastic material bydistending the belts in a direction transverse to the direction oforientation of the film by passing pressure means across and in contactwith at least one elastic belt so that the component of the velocity ofthe pressure means that is parallel to the direction of movement of thefilm is substantially equal to the velocity of movement of the film.

PATENTEnJAmz mn 7 7 3554419 suiznofa FIBRILLATED 22\ 2 GEAR H 2? BOXFIG.

INVENTORS E. ROBINSON D. E. PERRY A T TORNEKS PATENIEUJANIZIBYI 3554.419

FIBRILLATED FILM INVENTOKS' L.E. ROBINSON A TTORNEYS sum 3 or 3 PATENTEUJAN 1 2 ism INVEN'I'ORS L. E. ROBINSON 0. E. PERRY r W 4;; ATTORNEYS vFIG. 5

NONWOVEN FABRICS This application is a division of our copendingapplication $er. No. 442,588 filed Mar. 25, 1965 now US. Pat. No.3,424,358.

This invention relates to a method and apparatus for producing nonwovenfabrics from continuous sheet material.

It is known that many synthetic organic linear polymers possess a markedfissility when they have been uniaxially oriented to a high degree andthat films ofthese highly oriented films can be split into individualfibers or into a network of coherent fibers by suitable mechanical meanssuch as brushing, rubbing and the like.

Heretofore, in order to make a continuous, high-speed process ofsplitting an oriented film into fibers or a network of coherent fibers,i.e. fibrillating, a roller or other mechanical device for deforming theelastic belts, and therefore fibrillating the film therebetween, wasdisposed, relative to the belts so that the device rolled in a directionparallel to the direction of movement of the belts. For example, if asingle roller was utilized to deform the belts and therefore fibrillatethe film the long, major axis of the roller was disposed so that it wasperpendicular to the longitudinal axis and direction of movement of thebelts and the roller thus rotated in the same direction as the beltsmoved.

However, generally the film between the belts is oriented so that theorientation direction thereof is substantially parallel to longitudinalaxis and, therefore, the direction of movement of the belts. Since thedegree of a fibrillation of the film depends upon the degree ofdistension of the belts in a direction perpendicular to the orientationdirection of the film it is preferred and highly desirable to effectmaximum distension of the belts in a direction perpendicular to thelongitudinal axis thereof and, therefore, perpendicular to the directionof orientation of the film between the belts. Thus, a maximum degree offibrillation was not achieved in prior methods since those methodseffected maximum distension of the belts, and film therebetween, in adirection parallel and not perpendicular to the direction of movement ofthe belts.

It has now been found that a continuous, high-speed method offibrillating a film between two belts of elastic material by distendingthe belts to the maximum possible extent in a direction perpendicular tothe longitudinal axis thereof is effected when the moving belts with thefilm therebetween have at least one pressure means such as a rollerpassed across the path of movement of and in contact with the belts in adirection and with a velocity relative to the direction and velocity ofmovement of the belts such that the component of the velocity of thepressure means that is parallel to the direction of movement of thebelts is substantially equal to the velocity of the belts. By thisprocedure, when the pressure means contacts the belts it is moving inthe direction of movement of the belts at a velocity equal to thevelocity of the belts and thus the net effect is that the pressure meanstravels with the belts but at the same time across the belts in adirection of travel perpendicular to both the direction of travel of thebelts and the orientation of the film.

It was also found that the above method could be carried oilt by anapparatus utilizing a first pair of endless belts which are elastic andare adapted to meet on the exterior surfaces thereof and move along afixed line of travel and a pressure means which is adapted to cross thefixed line of travel of the endless belts and contact and distend same.The pressure means is controlled by a mechanism which coordinates thedirection and velocity of movement thereof relative to the endless beltsas above described. At least one of the endless, elastic belts can be anendless chain of plates, each plate covered by an elastic material sothat, in effect, the film is pressed between two elastic surfaces.

Accordingly, it is an object of this invention to provide a new andimproved method of fibrillating oriented film. It is another object ofthis invention to provide a new and improved apparatus for fibrillatingoriented film.

Other aspects, objects and the several advantages of the invention willbe readily apparent to those skilled in the art from the description,the drawing and the appended claims.

FIG. 1 is a side elevation of apparatus embodying the invcn' tron.

FIG. 2 is a perspective view of the relation'of the elastic beltscarrying the film and the roller carrying plates crossing those belts. I

FIG. 3 is a perspective view of another apparatus embodying theinvention.

FIG. 4 is a cross section of the pressuring apparatus used in FIG. 3.

FIG. 5 is a cross section ofa part of the apparatus of FIG. 3.

In FIG. 1 there is shown a pair of endless chains of plates 1.1 carriedby sprockets 2, 3, 4 and 5 which sprockets are in turn carried by asuitable frame not shown. Chains 1,1 are a series ofrotatingly-connected, rigid plates which substantially abut one anotherwhen traveling in a straight line between the supporting sprockets.Chains 1,1 are adapted to approach each other on their exterior surfacesin the general area 6 thereby moving individual and opposed plates 7,7on each chain into a close but spaced-apart relationship. Chains 1,1 andplates 7,7 move in this close but spaced-apart relationship along afixed line of travel and at a first primary velocity before separatingin the general area 8 and returning to the general area 6.

A pair of endless belts 9,9 which are made of an elastic material suchas rubber rotate about sprockets I0, 11, 12, 13. l4, l5, l6 and 17. Thissecond pair of belts is adapted to meet on their exterior surfaces inthe general area 6 and travel along a fixed line of travel at a secondprimary velocity and to intersect the line of travel of the pair ofbelts at an angle. hereinafter referred to as 0, of less than nd to passbetween the spaced-apart plates 7,7 of chains 1,1. A pressure means 18,further describedwith reference to FIG. 2, is carried by plates 7,7 onat least one of chains 1,1. Pressure means 18 is adapted to extend intothe space between spaced-apart plates 7,7 as indicated by 19 and isfurther adapted to rotate in a direction perpendicular to the directionof movement of belts 9,9. That part of pressure means 18 that extendsinto space 19 contacts belts 9,9 and forces same against a plate 7 onthe opposite side of belts 9,9 thereby applying pressure to belts 9,9while traveling with same in their direction of travel and at the sametime perpendicularly across belts 9,9.

It should be noted that the lower chain of plates may or may not havepressure means 18 and there can be substituted a stationary backup plateagainst which belts 9,9 are pressed by pressure means 18 in the upperchain of plates.

Thus, a continuous, longitudinally-oriented film 20 which is passedbetween belts 9,9 is fibrillated by pressure means 18 perpendicularlycrossing belts 9,9 thereby distending the belts to be maximum extent inthe direction perpendicular to the direction of travel of belts 9,9 andthe direction of orientation of film 20.

To insure that maximum pressure is applied by pressure means 18 to belts9,9 rotating pressure means 21,21 on the interior surfaces of chains 1,1are positioned on either side of belts 1,1 in the area where belts 9,9are passing between plates 7,7. Although the rotating pressure means21,21 can be any type of means known, it is preferably a series ofstationary rollers disposed throughout the whole length of the zone ofcoaction, i.e. intersection, between chains 1,1 and belts 9,9.

Chains 1,1 and belts 9,9 are driven by a single motor 22 which isconnected by 23 to gear box 24 which gear box is arranged internally ina known manner so that gear 10 is driven by pulley 25 and pulley belt 26at one velocity and sprocket 2 is driven by gear 27 and belt 28 atanother velocity. An ar rangement similar to that shown for gears 25 and27 and pulley belts 26 and 28 is arranged on the opposite side of gearbox 24, not shown, to rotate pulley 14 and sprocket 4 at the samevelocities, respectively, of pulley 10 and sprocket 2. The relativevelocity of belts 1,1 and 9,9 are adjusted through gear box 24 so thatthe component of the primary velocity of chains 1,1 which is parallel tothe fixed line of travel of belts 9,9 is equal to the primary velocityof belts 9,9 the primary velocities of chains 1,1 and belts 9,9 beingthat velocity parallel to the longitudinal axis of the belts and isdirectly related to the speed at which pulleys l and I4 and sprockets 2and 4 are rotated by pulleys on gear box 24.

In FIG. 2 there is shown continuous film between belts 9,9 and plates7,7. Two pressure-rotating means in the form of rollers 21,21 pressagainst plates 7,7 as they pass across belts 9,9.

Single plate has therein a pressure means 18 in a form of a sphericalball which freely rotates in plate 30 and therefore is adapted to rotatein a direction perpendicular to the direction of movement of belts 9,9.Separate plate 31 shows a pressure means 18 which comprises elongaterollers so oriented with respect to the direction of travel of the platethat they are free to rotate in a direction perpendicular to the line oftravel of belts 9,9. Separate plate 33 shows a pressure means 18 whichcomprises smaller rollers. In order to insure that maximum coverage ofbelts 9,9 with pressure means 18 is effected varying types of pressuremeans 18 can be employed as the same chain of plates as is shown in FIG.2; however, a single type of rolling means can be employed throughout ina chain of plates as shown in FIG. 1. Other types of rotating means arecontemplated by this invention and will be obvious to those skilled inthe art.

The direction of travel of chains 1,1 is indicated by arrow 35 and thedirection of travel of belts 9,9 is indicated by arrow 36, theintersection of which two arrows subtends the angle 0. Arrow 35 isparallel to the longitudinal axis of chains 1,1 and arrow 36 is parallelto both the longitudinal axis of belts 9,9 and the orientation directionof film 20.

Thus, for a given primary velocity of belts 9,9 indicated by V there isfor a given angle 0 a corresponding primary velocity for chains 1,1indicated as V which will yield a component designated as V, which isparallel to the primary velocity V and whichis equal in magnitude to VSimilarly, primary velocity V for chains 1,1 will have a component Vwhich is perpendicular to the line of movement 36 of belts 9,9 andtherefore indicates the velocity at which rolling means 18 passesperpendicularly across belts 9,9 thereby distending those belts to amaximum amount in this perpendicular direction. It can thus be seen thatthe only net relative movement of rotating means 18 while in contactwith belts 9,9 is perpendicular to the longitudinal axis of belts 9,9.

It should be noted that more than one set of chains 1,1 and/or belts 9,9can be employed. Also, more than one set of chains 1,1 can be employedon a single set of belts 9,9 and vice versa. Further, when more than oneset of chains 1,1 is employed with a single set of belts 9,9 varyingangles 0 can be employed and the various chains 1,1 can approach thesingle belt 9,9'from either side thereof.

This invention applies to any orientable film known in the art such asfilms of thermoplastic resins, for example, polyalkylenes such aspolyethylene, polyamides such as nylon, polycarbonates andpolyvinylalcohol. The only requirement for the films is that they beoriented at least uniaxially which orientation can be achieved by anyknown method such as by stretching the film in a cold or heated state. Apreferred method of orienting a film is disclosed in US. Pat. No.2,943,356 issued to Ole-Bendt Rasmussen on July 5, I960. The films canhave a thickness of from one-half to 10, preferably from I to 5, mils.

The product of this invention is a fibrillated film which has greatporosity and flexibility in combination with good strength propertiesand is well suited for use as a nonwoven textile material, filtermaterial and the like.

The velocities of movement of either set of belts is dictated only bythe specific apparatus used and vary widely since the apparatus andmethod are extremely flexible in that the relative velocities of bothsets of belts and the angle 0 between same can all three be varied untilthe desired combination of velocities and angle above described isachieved. All that is required of the primary velocities and their angle6 is that the ratio of the velocity of belts 9.9 to the velocity ofchains 1.1 be equal to the cosine of the angle between them, i.e. thecosine of 0.

FIG. 3 shows an embodiment of the invention wherein the lower elastic,endless belt 9 of FIG. 1 has been replaced by surfacing each plate 7 ofthe lower endless chain of plates of FIG. 1 with a section of elasticmaterial 40. The section of elastic or resilient material which at leastpartially, preferably substantially completely, covers each lower plate7 is preferably composed of the same type of elastic material as upperendless belt 9.

In FIG. 3 the upper endless chain of plates utilizes single sprockets 41and 42 and a single chain 43 in lieu of two chains 1, two sprockets 4and two sprockets 5 as shown in FIG. 1. Side plates 44 and 45 carry apressure means that straddles chain 43 and not only applies a verticalpressure to plates 7 but also laterally stabilizes those plates. Thispressure means is more specifically shown in FIG. 4.

A means for holding belt 9 against surfaces 40 of lower plates 7 isshown and includes a chain 46 traversing drive sprocket 47, sprockets 48and 49, and an unshown sprocket 5 I behind sprocket 41. As shown in FIG.5, chain 46 carries an inwardly extending pressure member which bearsagainst the inner surface of belt 9 when that belt is in contact withthe surfaces 40 of plates 7. Rotating pressure members 51 are fixed toside plate 52 through arms 53 and are adapted to bear against thepressure arm carried by chain 46 thereby binding belt 7 between thepressure arm and a plate 7. Pressure members 51 are rotated by sprockets54 which engage and are rotated by the movement of chain 46. Chain 46and belt 9 are both driven by belt 55 so that the chain and the beltmove at substantially the same speed. It should be noted that in orderto effect substantial identity of speeds of the chain and the belt, theratios of the diameters of pulleys 56 and 57 to sprocket 47 and roller17, respectively, must be substantially the same. Gear and/or drive box58 can be operatively.connected to the same driving means that runs theother parts of the machine, as shown with gear box 24 in FIG. 1, so thatthe speeds of the upper and lower chains of plates, belt 9 and chain 46are all coordinated relative to one another to produce the results ofthe invention.

FIG. 4 taken along line 4-4 of FIG. 3, shows side plates 44 betweenwhich is fixed a support member 60 which straddles chain 43 and which,through angled rollers 61 and 62, contacts shoulders 63 and 64 of plate7. The angled nature of rollers 61 and 62 provides both the verticalforce for pressing rollers 18 against belt 9 and for preventing plate 7from moving laterally relative to support member 60.

FIG. 5, taken along line 5-5 of FIG. 3, shows sprockets 3 engagingplates 7 through parallel chains attached to plates 7. Side plates 52and 70 fixedly support members 71 and 72, respectively, each of whichrotatably carry a roller 73. Rollers 73 engage shoulders 74 of plates 7thereby applying both vertical forces and laterally opposing forces toplates 7. Thus, plates 7 are forced upward towards the upper chain ofplates and prevented from laterally moving from their direction ofmovement.

Pressure arm 75 carried on the interior side of chain 46 is disposedabove shoulder 76 of plate 7 so that it will press belt 9 (not shown)into contact with shoulder 76 thereby holding belt 9 in a fixed relationto and against plates 7. Rotating pressure member 51 driven by chain 46through sprocket 54 en sures positive pressing of arm 75 against bothbelt 9 and shoulder 76. Although ann 75 and shoulder 76 are shown tohave teeth in the area in which belt 9 is gripped, it should be notedthat other or no auxiliary gripping means can be employed.

EXAMPLE An apparatus similar to that shown in FIG. 1 was employed inwhich belts 9,9 were endless rubber belts and chains 1,1 were made up ofa series of pivotally connected plates each plate having mounted thereinl2 cylindrical rollers 1 1/16 inches long and 1 l/l6 inches in diameter.The rollers were arranged in a series similar to that shown in plate 33of FIG. 2 and each plate of both chains has a similar arrangement ofsimilar rollers. The rollers were laterally spaced from one another adistance of 1.142 inches. Chains 1,1 were oriented with respect to belts9,9 so that they crossed those belts at an angle 6 of 35. The velocity,V,,, of the belts 9,9 was 150 feet per minute and the velocity, V of thechains was 183.2 feet per minute.

Polyethylene film was uniaxially oriented parallel to its longitudinalaxis by stretching of same, having a density of 0.96 and a thickness of3 mils. The film removed from between belts 9,9 after passing betweenchains 1,1 was fibrillated in that it was a weblike network of coherentfibers randomly drawn to one another along a longitudinal length therebyforming a nonwoven fabric having good strength properties combined witha significant amount of porosity and flexibility.

Reasonable variations and modifications are possible within the scope ofthis disclosure without departing from the spirit and scope thereof.

We claim:

1. Apparatus for making fibrillated film comprising a frame, a pair ofelastic means carried by said frame and adapted to meet in an abuttingrelationship and pass along a fixed line of travel in that relationshipbefore being separated and returned to be moved again into said abuttingrelationship, pressure means carried by said frame and adapted to crosssaid fixed line of travel of said elastic means and to contact anddistend said elastic means in a direction substantially perpendicular tothe direction of movement of said elastic means, and means carried bysaid frame to move said pressure means in a direction and at a velocityacross said elastic means such that the component of velocity of saidpressure means which is parallel to the direction of movement of saidelastic means is substantially equal in magnitude to the velocity ofsaid elastic means in said direction of movement.

2. Apparatus according to claim 1 wherein said elastic means is anopposing pair of endless belts.

3. Apparatus according to claim 1 wherein said elastic means is anendless belt and an opposing endless chain of plates each plate carryinga section of resilient material between itself and the endless belt.

4. Apparatus according to claim 1 wherein said pair of elastic meanscarried by said frame is adapted to meet and travel along a fixed lineof travel at a first primary velocity, at least one pressure means iscarried by said frame and adapted to move along a fixed line of travelat a second primary velocity, a backup means is carried by said frame,said elastic means and pressure means are mounted on said frame so thatthey intersect the line of travel of each other at the location of saidbackup means at an angle of less than 90 and said elastic means passbetween and are pressed together by said pressure means and said backupmeans, and means is provided to move both said elastic means and saidpressure means it a rate such that the component of the primary velocityof said pressure means which is parallel to the fixed line of travel ofsaid elastic means is substantially equal to the primary velocity ofsaid elastic means.

5. Apparatus according to claim 1 wherein a pair of endless chains ofplates is carried by said frame and adapted to approach each other ontheir exterior surfaces and hold opposing plates on each chain in aclose but spaced-apart relationship while moving along a fixed line oftravel in said relationship at a first primary velocitybefore'separuting and returning to again be moved into said spaced-upartrelationship, said elastic means is a pair of elastic endless beltscarried by said frame and adapted to meet on the exterior surfacesthereof and travel along a fixed line of travel at a second primaryvelocity which has a component which is parallel to the line of travelof said pair of chain of plates, said pair of belts and said pair ofchains of plates being mounted on said frame so that they intersect theline of travel of each other at an angle of less than nd said belts passbetween said spaced-apart plates of said chains, rotating means carriedby the plates in at least one of said pair of chains of plates andextending into the space between said plates when in said spacedapartrelationship and adapted to rotate in a direction perpendicular tot'nedirection of movement of said belts, rotating means fixed on theinterior sides of said pair of chains of plates mounted in the areawhere said chains intersect said pair of belts and adapted to force saidchains toward one another and force said rotating means in said platesagainst said belts along the length of intersection of said belts andsaid chains, and means to move both said belts and said chains at a ratesuch that the component of the primary velocity of said chains which isparallel to the line of travel of said belts is substantially equal tothe primary velocity of said belts.

6. Apparatus according to claim 1 wherein said pressure means carried bysaid plates comprises atleast one roller.

'7. Apparatus according to claim 3 wherein said endless belt is heldrelative to said chain of plates by a holding means comprising anendless chain carrying a pressure arm adapted to approach said chain ofplates, and a rotatable pressure means rotated by movement of said chainand adapted to engage the pressure arm of said chain and force same toapproach said chain of plates.

8. Apparatus according to claim 1 wherein a pair of endless chains ofplates is carried by said frame and adapted to approach each other ontheir exterior surfaces and hold opposing plates on each chains in aclose but spaced-apart relationship while moving along a fixed line oftravel in said relationship at a first primary velocity beforeseparating and returning to again be moved into said spaced-apartrelationship, said elastic means comprises an elastic endless beltadapted to meet one of said pair of chains of plates on the exteriorsurfaces thereof and travel between said close but spaced-apart pair ofchains of plates and travel along a fixed line of travel at a secondaryprimary velocity which has a component which is parallel to the line oftravel of said pair of chains of plates, the plates of one of said pairof chains of plates carrying an elastic member between the plate and theendless belt, said belt and said chains of plates being mounted on saidframe so that they intersect the line of travel of each other at anangle of less than 90, rotating means carried by the plates in at leastone of said pair of chains of plates and extending into the spacebetween said plates when in said spaced-apart relationship and adaptedto rotate in a direction perpendicular to the direction of movement ofsaid belt, rotating means fixed on the interior sides of said chains andmounted in the area where said chains intersect said belt and adapted toforce said chains towards one another and therefore force said rotatingmeans in said plates against said belt along the length of intersectionof the said belt and said chains, and means to move both said belt andsaid chains at a rate such that the component of the primary velocity ofsaid chains which is parallel to the line of travel of said belt issubstantially equal to the primary velocity of said belt.

Disclaimer and Dedication 3,554,419.-Ler0 E. Robinson and Dan E. Perry,Bartlesville, Okla. NON- VVOVE FABRICS. Patent dated Jan. 12, 1971.Disclaimer and dedication filed Dec. 28, 1971, by the assignec, PhillipsPetroleum 001m pany. Hereby disclaims said patent and dedicates to thepublic the remaining term of said patent.

[Oflicial Gazette April 11, 19753.]

2. Apparatus according to claim 1 wherein said elastic means is anopposing pair of endless belts.
 3. Apparatus according to claim 1wherein said elastic means is an endless belt and an opposing endlesschain of plates each plate carrying a section of resilient materialbetween itself and the endless belt.
 4. Apparatus according to claim 1wherein said pair of elastic means carried by said frame is adapted tomeet and travel along a fixed line of travel at a first primaryvelocity, at least one pressure means is carried by said frame andadapted to move along a fixed line of travel at a second primaryvelocity, a backup means is carried by said frame, said elastic meansand pressure means are mounted on said frame so that they intersect theline of travel of each other at the location of said backup means at anangle of less than 90* and said elastic means pass between and arepressed together by said pressure means and said backup means, and meansis provided to move both said elastic means and said pressure means it arate such that the component of the primary velocity of said pressuremeans which is parallel to the fixed line of travel of said elasticmeans is substantially equal to the primary velocity of said elasticmeans.
 5. Apparatus according to claim 1 wherein a pair of endlesschains of plates is carried by said frame and adapted to approach eachother on their exterior surfaces and hold opposing plates on each chainin a close but spaced-apart relationship while moving along a fixed lineof travel in said relationship at a first primary velocity beforeseparating and returning to again be moved into said spaced-apartrelationship, said elastic means is a pair of elastic endless beltscarried by said frame and adapted to meet on the exterior surfacesthereof and travel along a fixed line of travel at a second primaryvelocity which has a component which is parallel to the line of travelof said pair of chain of plates, said pair of belts and said pair ofchains of plates being mounted on said frame so that they intersect theline of travel of each other at an angle of less than 90* and said beltspass between said spaced-apart plates of said chains, rotating meanscarried by the plates in at least one of said pair of chains of platesand extending into the space between said plates when in saidspaced-apart relationship and adapted to rotate in a directionperpendicular to the direction of movement of said belts, rotating meansfixed on the interior sides of said pair of chains of plates mounted inthe area where said chains intersect said pair of belts and adapted toforce said chains toward one another and force said rotating means insaid plates against said belts along the length of intersection of saidbelts and said chains, and means to move both said belts and said chainsat a rate such that the component of the primary velocity of said chainswhich is parallel to the line of travel of said belts is substantiallyequal to the primary velocity of said belts.
 6. Apparatus according toclaim 1 wherein said pressure means carried by said plates comprises atleast one roller.
 7. Apparatus according to claim 3 wherein said endlessbelt is held relative to said chain of plates by a holding meanscomprising an endless chain carrying a pressure arm adapted to approachsaid chain of plates, and a rotatable pressure means rotated by movementof said chain and adapted to engage the pressure arm of said chain andforce same to approach said chain of plates.
 8. Apparatus according toclaim 1 wherein a pair of endless chains of plates is carried by saidframe and adapted to approach each other on their exterior surfaces andhold opposing plates on each chains in a close but spaced-apartrelationship while moving along a fixed line of travel in saidrelationship at a first primary velocity before separating and returningto again be moved Into said spaced-apart relationship, said elasticmeans comprises an elastic endless belt adapted to meet one of said pairof chains of plates on the exterior surfaces thereof and travel betweensaid close but spaced-apart pair of chains of plates and travel along afixed line of travel at a secondary primary velocity which has acomponent which is parallel to the line of travel of said pair of chainsof plates, the plates of one of said pair of chains of plates carryingan elastic member between the plate and the endless belt, said belt andsaid chains of plates being mounted on said frame so that they intersectthe line of travel of each other at an angle of less than 90*, rotatingmeans carried by the plates in at least one of said pair of chains ofplates and extending into the space between said plates when in saidspaced-apart relationship and adapted to rotate in a directionperpendicular to the direction of movement of said belt, rotating meansfixed on the interior sides of said chains and mounted in the area wheresaid chains intersect said belt and adapted to force said chains towardsone another and therefore force said rotating means in said platesagainst said belt along the length of intersection of the said belt andsaid chains, and means to move both said belt and said chains at a ratesuch that the component of the primary velocity of said chains which isparallel to the line of travel of said belt is substantially equal tothe primary velocity of said belt.